hermanjs/src/url-mapping.js

Singleton models with Backbone and possibly other frameworks

var myGlobal;
if (typeof window !== typeof undefined) {
  myGlobal = window;
} else if (typeof global !== typeof undefined) {
  myGlobal = global;
} else {
  throw 'global unknown '
}

var M = function (maybeAPI) {
  var m = Object.create(M);
  m.api = maybeAPI || {};
  m.cache = {};
  M.mapOverResourceTypes(function (resourceType) {
    decorateWithPluralFormMethods(resourceType, m);
    decorateWithSingularFormMethods(resourceType, m);
  }, m);
  M.initializationSubscribers.map(function (f) {f(m);});
  return m;
};

M.mapOverResourceTypes = function (callback, m) {
  m = m || this;
  return Object.keys(m.api.resources).map(callback);
};
M.initializationSubscribers = [];

function decorateWithSingularFormMethods (resource, m) {
  m[resource] = function (maybeId) {
    var state = Object.create(this === global ? m : this);

    state.urlFragments = (state.urlFragments || [m.api.prefix]).concat([resource]);
    state.resourceType = resource;

    function appendId (id) {
      state.urlFragments.push(id);
    }

    var strategy = {
      number: appendId,
      string: appendId,
      undefined: function () {/* fall through */}
    } [typeof maybeId] || throwInvalidArgument;

    strategy(maybeId);

    function throwInvalidArgument () {
      throw new Error('This function only accepts a string or a number id.');
    }

    return state;
  };
}

function decorateWithPluralFormMethods (resource, m) {
  var pluralForm = plural(resource);
  m[pluralForm] = function (maybeQuery) {
    var state = Object.create(this === global ? m : this);

    state.urlFragments = (state.urlFragments || [m.api.prefix]).concat([pluralForm]);
    state.resourceType = resource;
    state.isPlural = true;

    var strategy = {
      object: function (query) {
        state.urlFragments.push('?' + serialize(query));
      },
      undefined: function () {/* fall through */}
    } [typeof maybeQuery] || throwInvalidArgument;

    strategy(maybeQuery);

    function throwInvalidArgument () {
      throw new Error('This function only accepts a plain old javascript query object.');
    }

    return state;
  };
}

function serialize (object, prefix) {
  return Object.keys(object).map(function (key) {
    var value = object[key];
    if (prefix) {
      key = prefix + '[' + key + ']';
    }
    if (typeof value === 'object') {
      return serialize(value, key);
    }
    return encodeURIComponent(key) + '=' + encodeURIComponent(value);
  }).join('&');
}

function plural (singularForm) {
  return singularForm + 's';
}
module.exports = M;